Nipple containers with sterile opening devices

ABSTRACT

Nursing unit for use in the feeding of liquid foods to infants wherein the unit has at least two separate and sterile compartments sealed from each other, one of which contains a liquid food, and an opening means located in either of the two compartments which can be actuated to create an opening between the two compartments without violating the sterility of either compartment. The nursing unit comprises in combination a sealed container enclosing liquid food in a sterile condition forming a first compartment and a nipple attached to the top of the sealed container to form with the top a second sterile compartment. The opening device acts upon a section of the top surface of the container to create an opening therein to provide a passageway for the liquid food from the container to the second compartment and the interior of the nipple. Nipple structures having venting means incorporated therein are provided for permitting venting of the unit during feeding, when necessary. Inexpensive nipples composed of a thin film shaped in the form of a teat and filled with a porous foam for use in the nursing unit are disclosed. An overcap for the nipple on the container is also provided to maintain the outer surface of the nipple sterile.

ilnited tree areal 6ehaar [151 [4 1 Jan, 1, W7

Charles lil. Schaar, Libertyville, ill. [73] Assignee: The KendallCompany, Boston, Mass. [22] Filed: Aug. 12, 1964 [21] App1.No.: 389,085

[72] Inventor:

2,939,598 6/1960 Dowleavy 215/11 3,146,904 9/1964 Hansen et al. .215/113,187,918 6/1965 Moore ....215/l1 3,194,424 7/1965 Barr ....2l5/113,266,910 6/1963 Barnby ..99/171 Primary Examiner.lames B. MarbertAttorney-James I. Fawcett, Robert D. Chodera, T. W. Underhill and JeromeM. Teplitz [57] ABSTRACT Nursing unit for use in the feeding of liquidfoods to infants wherein the unit has at least two separate and sterilecompartments sealed from each other, one of which contains a liquidfood, and an opening means located in either of the two compartmentswhich can be actuated to create an opening between the two compartmentswithout violating the sterility of either compartment. The nursing unitcomprises in combination a sealed container enclosing liquid food in asterile condition forming a first compartment and a nipple attached tothe top of the sealed container to form with the top a second sterilecompartment. The opening device acts upon a section of the top surfaceof the container to create an opening therein to provide a passagewayfor the liquid food from the container to the second compartment and theinterior of the nipple. Nipple structures having venting meansincorporated therein are provided for permitting venting of the unitduring feeding, when necessary. Inexpensive nipples composed of a thinfilm shaped in the form of a teat and filled with a porous foam for usein the nursing unit are disclosed. An overcap for the nipple on thecontainer is also provided to maintain the outer surface of the nipplesterile.

7 Claims, 16 Drawing Figures PATENTEU JAN i 8 m2 SHEET 1 [IF 3 PATENTEDJAN 1 81972 SHEET 2 UF 3 NIPPLE (IGNTAINERS WITH STIIIQILIE OPENINGDEVICES This invention is concerned with liquid baby food packagesparticularly with such packages to which a feeding nipple is attached,the food and nipple being maintained in sterile condition until actualuse at ambient temperatures.

Recently there have been revolutionary changes in baby feedingtechniques. No longer is it necessary for mothers to wash and sterilizecontainers and nipples, to sterilize the milk or other liquid food, torefrigerate the tilled nipple packages and finally to warm the food inthe container at feeding time. A great deal of inconvenience may now beavoided with presterilized combinations which are essentially sealedfoodfilled containers with sterile tops and containing sterile food, asterile nipple and simple means usually involving a plastic collar forfastening the nipple to the container top after the latter has beenperforated. This combination need not be refrigerated because thecontainer is sealed until just prior to feeding hence the originalsterility of contents is not compromised. Likewise, warming is notnecessary. After the feeding, the entire combination is discarded.

Convenient as these modern packages and techniques are for feedingbabies, there is one difficulty connected with opening the sealedcontainer which is undesirable and in accordance with the teachings ofthis invention, unnecessary. Since the container must be opened as lateas possible before feeding the baby to preserve the liquid contents insterile condition, it is present practice to remove the coveringpreserving the container top in sterile condition and then to puncturethe sterile top with a sterile instrument after which the nipple issecured to the top and its cover removed. Alternatively, the whole topis removed and replaced with a sterile nipple top. It is obvious at oncethat by the puncture technique the top of the container and the bottomof the nipple are momentarily exposed to the air and hence to bacteria.Furthermore, when puncture means are utilized, the puncturing means mustbe sterilized and unless a sterile instrument is furnished, utilizationof some sterilizing technique on the part of the mother is required.Obviously, also when the entire container top is removed and replacedwith a sterile nipple, the entire contents and the bottom of the nippleare momentarily exposed to bacteria. While this is probably not seriousin view of the fact that the food is consumed before any bacteria has anopportunity to multiply to any substantial concentration, it doesrepresent bacterial exposure which in accordance with the teachings ofthis invention is unnecessary. Furthermore, the person prepar ing thebabys food is put to unnecessary inconvenience at the least. This isparticularly frustrating where facilities are inadequate as whentraveling.

It is an object of this invention to provide sealed containerscontaining sterile baby food and an attached sterile nipple and meansfor opening the container without exposing either the sterile contentsor the sterile nipple to bacterial contact.

It is a further object of the invention to provide a container forsterile liquid baby food with an attached sterile nipple which may bestored indefinitely and then opened for immediate feeding of any timewithout risk of bacterial contamination of the nipple and the liquidcontents.

It is a further object of this invention to provide a container forsterile liquid baby food with a thermoplastic nipple heatsealed to thesterile container top and providing a strainer for the liquid food, thecontainer being capable of being opened without exposing the nipple orcontents to bacterial contact.

Other objects of the invention will be evident from an inspection of thespecification of the drawings. In the latter:

F IG. 11 represents an exploded perspective view of a typical nursingunit of the invention.

FIG. 2 illustrates in cross section and unit of FIG. 1 in assembledrelationship and ready to be opened.

FIG. 2a illustrates the opening means of FIG. 2 after the openingoperation.

FIG. 2b illustrates in greater detail the event valve of FIG. 2.

FIG. 3 illustrates partially in cross section another typical nursingunit of the invention.

FIG. 4 represents an exploded perspective view of another typicalnursing unit of the invention.

FIG. 5 illustrates in cross section the unit of FIG. l in assembledrelationship and ready to be opened.

FIG. 6 illustrates in partial cross section a container top with atypical opening of the invention attached.

FIG. 7 illustrates in cross section a container top of the in ventionequipped with an electrical opening device.

FIG. it illustrates the nipple portion of another typical nursing unitof the invention in partial cross section.

FIG. 9 illustrates the nipple portion of still another typical nursingunit of the invention in partial cross section.

FIG. I0 is a top view ofa typical container top with an opening deviceof the invention.

FIG. Ill is a partial side view in partial cross section of the top andopening device of FIG. 10.

FIG. 12 illustrates in partial cross section a partial side view of acontainer top with a typical opening device of the inventron.

FIG. I3 illustrates in partial cross section a partial side view of anursing unit of the invention with a typical opening device.

FIG. ll l illustrates in partial cross section a partial side view of anursing unit of theinvention with a typical opening device.

The objects of the invention are achieved by providing nursing unitsealed containers of sterile liquid baby food having means forpreserving the attached nipple in sterile condi tion, the unit includingmeans for opening the sealed container by moving a sterile device withinthe sterile area so as to create an opening in the container such thatsterile liquid will flow only in sterile areas through the opening intothe nipple.

An important feature of this invention is the provision of a nursingunit comprising three sterile areas, one being the area between thenipple cap and the nipple including the outside of the latter, a secondsterile area being the inside of the sealed liquid container and thethird being the inside of the nipple and the area communicating with itat its base including at least a portion of the adjoining wall (usuallythe top) of the container. The sterile opening means is disposed withineither the second or third sterile area and functions when operated tocreate and opening in the container wall in the area separating thesecond and third sterile areas. The opening means preferably is operatedwithout violating the sterility of any of the sterile areas butobviously one might remove the nipple cap just prior to operating theopening means without serious bacterial contamination of the outside orinside of the nipple. For purposes of this invention, therefore, it isessential only that the opening means be operative without itselfviolating the-sterility of areas two and three. Any practical means foropening which is operative in the space of the second or third sterileareas without violating their sterility is suitable. Openings may bemade by piercing, tearing, cutting, punching, separating, abrading,peeling, sliding, twisting, melting and the like. Typical means areillustrated but for purposes of this invention any means operative inthe sterile area is considered equivalent to those illustrated anddescribed. The opening created permits the liquid food to pass from thecontainer through the opening into the nipple by a completely sterilepath. The sterility of the nipple and the contents may be preserveduntil the last instant when the nipple cap is removed after the openingis created and the nipple is immediately placed in the baby s mouth.

Referring once more to the drawings:

In FIGS. 1 and 2, a typical nursing unit 10 of the invention includes anipple cap 11, a nipple 12, a container 20 with preferably a permanentlyfastened cover I3 and an opening device 14 fastened to the cover 13. Inpractice, finger pressure through the interposed nipple cap wall and thenipple causes the opening device handle to exert an upward force on thethinned cup IS. The cup 15 is an integral part of the cover 13 and actslike a hollow rivet to hold the opening device in place but when thedevice handle is pressed down, the thinned portion tears creating anopening. FIG. 2a illustrates the general type of opening created. Thenipple in the embodiment has an orifice 17 and a base 24 which holds aresilient material such as polyurethane foam 18 in place. The base has ahole 22 for ingression of the liquid food. The nipple depending skirt 19which is sealed to the skirt of the container cap 13. This may be doneby shrink-sealing, heat-sealing, gluing, or other means which creates anonleak bacteria-impervious jointure. The nipple skirt in thisembodiment is equipped with a vent so that air may enter to replace theliquid food removed through the nipple action of the baby. This vent,shown more clearly in FIG. 2b, consists of a hole 37 in the nipple skirtand a film 38 covering the hole and sealed on its sides but not at itsends to the nipple skirt. As a partial vacuum is formed by the liquidremoved, the film of the vent is drawn away from the hole to let in airand relieve the partial vacuum. The provision of a vent in any of thenursing units of this invention while preferred is optional, however,and is not critical to the inventron.

The nipple of FIG. 2 may be covered by any type nipple cap whichpreserves the sterility of the nipple. Preferably the nipple cap isformed of a thin flexible material which may be distorted in operatingthe opening means without violating the sterility of the enclosed space.But the benefits of the invention are still present even though the capmay be so inflexible that it must be removed just prior to opening thecontainer. For purposes of the invention, therefore, it is necessaryonly that the opening means to be operable with the nipple in placewithout violating the sterility of sterile 'areas two and three exceptfor the nipple orifice. In the embodiment shown in FIGS. 1 and 2, thenipple cap is heat shrunk over the container cover andthe nipple skirtin the skirt area 23. The cap is removed by pulling the tab 16 whichcauses the cap to tear away helped by the notch 21.

In FIG. 3, the nursing unit 25 is a somewhat different embodiment of theinvention in that a typical rubber nipple 27 might be used. This nipplewhich is equipped with a feeding orifice 33 and a vent 34 snaps into aflexible collar 28 made of material such as polypropylene. The collar inturn snaps over the upstanding rolled edge 31 of a container preferablyof tinplate with an aluminum top 32 to form a leakproof seal between thecollar and the container. A hard plastic or preferably metal washer 29with piercing teeth 30 is disposed under the nipple base in position tomake openings in the top 32 when pressed downwardly. A nipple coveringor cap 26 forms a bacterial impervious cover. The cap preferably is ofthin film but may be of paper or other thin material. The cap isretained in bacteria impervious relationship with the container by aplastic shrink band 35 which was a tear tab 36 by which it may be tornfree. As in the nursing unit of FIG. 2, the nursing unit of FIG. 3includes a sealed container of sterile liquid food and an area coveredby the nipple cap which is sterile. This embodiment may include a spongestrainer as is shown in FIG. 5 or it might include a plastic perforatefilm strainer. The container of this embodiment may be opened bypressing down with the thumbs or fingers at each side as is illustrated.The piercing teeth 30 readily penetrate aluminum and thin tinplate.Obviously, the container might be made of waxed paperboard or ofplastic.

In the embodiment illustrated in FIGS. 4 and 5, the nursing unit 40includes a nipple 42, a nipple cap 41, a shrink band 43, a sealedcontainer 47 with a screw top 46 and an opening device 48 resting in adepressed and thinned area of the top 46. The nipple may be aconventional rubber nipple with a feeding orifice 44 as is illustratedwith or without the foam filter 54 and fitted with a skirt to snap overthe screw top 46. Alternatively, it may be a thin film nipple as inFIGS. 1 and 2 with a foam filling and the skirt may be heat-shrunk overthe screw top. A vent-valve comprising a film 52 covering a hole 53 inthe nipple base may be adhered with latex or if plastic film is involvedin the nipple base may be heat-sealed or otherwise glued or fastenedalong the sides but not along the ends similar to FIG. 2b. The nipplecap 41 fits snugly over the screw top 46 and is held in bacteriaimpervious relationship to the screw cap skirt by the shrink band 43which has a tearing notch 51 and a tab 50. The area under the nipple capis sterile including the opening device 48, the nipple and foam, and thetop of the screw top 46. The sealed liquid container contains sterileliquid food. The container is opened by pushing down on the openingdevice 48 which is an enlarged tack of metal or hard plastic. The screwcap is preferably of aluminum.

In the assembly 55 of FIG. 6 only the container top 56 with the openingdevice 58 is illustrated. It is to be understood that the top 56 may besubstituted for the container top 13 of FIGS. 1 and 2 in a completenursing unit as is illustrated in those figures. In practice it isobvious that the finger does not press directly against the openingdevice 58 but rather through the interposed nipple at least andpreferably through both the nipple and nipple cap. The opening device 58consists of a plastic pop-plug fastened into a hole 57 in the top 56.

In FIG. 7 is illustrated a container top 60 which likewise may besubstituted for the top 13 of FIGS. 1 and 2 in a complete nursing unitas is illustrated in those figures. As can be seen from theillustration, a cup-shaped depression or well 62 is formed in the topportion 61 of the container top. A short piece of insulated wire 63 issecured to the container top preferably by heat sealing and a bare end64 projects into the well and contacts the thin bottom of the well.Another bare end 65 projects from under the bottom edge of the nipplecap. Likewise, a portion of the bottom edge of the container top is leftexposed. When the end 65 and the bottom edge of the top are contacted bythe electrical contacts 67 and 68 and the switch 69 is closed, theelectrical source 66 causes the thin well bottom to the perforated bymelting. In practice tinplate is the preferred material for thecontainer top, but other metals or heavy metal foil may be substituted.Depending upon the thinness and resistance of the top, a voltage as lowas 40 volts may cause perforation or one as much as 120 volts may benecessary. Obviously, where plastic is employed for the container top, ahigh-resistance wire in coil, loop, or other form may be used to melt anopening. For instance, a No. 32 steel wire approximately 5 inches inlength when formedinto a coil and placed in contact with a 30 milpolypropylene container top became hot enough when energized by about 2volts AC to melt an opening in about l5 seconds. These methods may beadvantageous in hospitals where a great number of nursing units must beprepared at about the same time.

In FIG. 8 it is to be understood that the complete nursing unit includesa sealed container containing a sterile liquid food and that the wall isa wall of that container. The unit includes a nipple 76 of the thin filmtype with a foam filling 78 and a nipple feeding orifice 77. The nippleof this embodiment is unusual in that it terminates in a flat flange 79which is sealed, preferably heat-sealed to the container wall 80 and theopening device 81 projects up into the base of the nipple. The nipplecap 82 may be heatsealed or otherwise glued to the wall of the containeralso or it may extend over the container top as in FIGS. 2 or 3 beingheat-shrunk to the container top or fastened by a heat-shrunk band.Preferably a tear tab is furnished to permit easy removal of the nipplecap. As is illustrated by the dotted lines, the nipple and preferablythe nipple cap may be distorted sufficiently to force the opening deviceaway from the wall 80 creating an opening. It is preferred that theopening device be of hard plastic sealed, preferably heatsealed, to thecontainer wall to cover an aperture in the latter.

In FIG. 9 the complete nursing unit 85 includes a nipple 87 of thin filmwith a feeding orifice 89 and a foam filling 88. Again the nipple base90 is sealed, preferably heat-sealed, to a wall 91 of the sealedcontainer containing the sterile liquid baby food. Again as in thenursing unit of FIG. 8, the nipple cap 86 covers at least the nipple andmaintains the area beneath it sterile. In the embodiment illustrated inthis figure, however, the container wall is provided with a cup 92having a thin depressed center portion which together with theperforated disk 94 holds the opening device 93, a large tack of metal orhard plastic, in place. This opening device is operated by pressingdownward through the nipple cap and nipple on the device so that itspoint pierces the container wall 91. A vent is provided in the nipple ofthis embodiment consisting of a hole 96 in the nipple wall and acovering film sealed at the sides but not at the ends to cover the holeas is shown more clearly in FIG. 2b. The vent is optional but should belocated outside the area normally in the babys mouth. Preferably, itshould be just above the perforated disc 94.

In FIGS. and 11, it is to be understood that the container top 100 andthe opening device 105 are part of a complete nursing unit such as isillustrated in FIG. 2. The container top is seen to consist of twolayers, a top layer 101 and a more easily torn or punched layer 106. Thetop layer may be of tinplate and the bottom plate of aluminum, forexample. In the embodiment shown, the top layer is scored in a boatshape by the score 102. The opening device is riveted by rivet 104 tothe container top. The device preferably has a pointed end. When thehandle 103 of the device is pushed in the direction of the arrow, not bythe finger in direct contact as illustrated but by the finger againstthe interposed nipple cap and nipple, the top layer tears along thescore 102 and helps to tear or puncture the bottom layer 106 thuscreating an opening in the sealed container in the sterile area.

In FIG. 12, likewise, the assembly 110 consisting of a container top 111and an opening device 112 is to be understood as part of a completenursing unit such as is illustrated in FIG. 2 with the container top ofthat illustration replaced by the assembly 110. In practice, the flatflange 114 of the opening device which may be of hard plastic or metalis sealed with the seal 113 to the container top. When the button of theopening device is pressed down, the seal is broken and an opening iscreated.

In FIG. 13, the nursing unit 115 includes a sealed container 118containing sterile liquid baby food, a foam-filled nipple 116 and anipple cap 117. A hole 119 in the container top is covered by a flatflange 120 which is connected by a rod 121 to a weight 122. The flange120 is sealed to cover the hole 119. When the container 118 is strucksharply on its side, the inertia of the weight tears loose the sealholding the flange 120 in place thus creating an opening.

In FIG. 14, the nursing unit 125 includes a sealed container 128 withflexible walls containing sterile liquid baby food, a foam-filled nipple126, and a nipple cap 127. A hole 129 in the container top is covered bya flat face of the opening device 131) which is sealed over the hole andwhich has an elongated arm extending near the container wall. When it isdesired to open the container, a finger is pressed against the elongatedarm pushing it inward and breaking the seals around the hole 129.

While metal is preferred as the material of the container wall in whichthe opening is created in the nursing unit of this invention, obviouslya great many of the opening devices could be used with plastics or withwax-coated or plasticcoated paperboard. It is intended to include inthis invention nursing units utilizing such materials.

In certain of the embodiments illustrated, a well or depression isshown. This well is a convenience but is not a necessity and may beeliminated, if desired.

I claim:

1. A nursing unit including:

a. a sealed container defined by top, bottom and side walls, saidcontainer enclosing within said wall a primary sterile zone containingsterile liquid baby food;

b. A nursing nipple having an upstanding teat and a base, said nipplebeing attached to said container with said base positioned toward andover the outside surface of the top wall of the container and the teatextending away from the container to provide a secondary sterile zonebounded by inside walls of said nipple and the outside surface of thetop wall of the container over which the attached nipple is located;

c. sterile opening means disposed within one of said sterile zonescomprising an arm means having one part thereof fixed to the top wall ofsaid container over which the attached nipple IS located and an arm partextending beyond the fixed part disposed at an angle to the surface ofsaid top wall of the container to provide a lever arm which is operablewithout violating the sterility of either of said zones by applicationof a load thereto to cause the top wall of the container to rupture: atthe place where the .arm means is fixed thereto to create an openingtherethrough and to displace said fixed part of the arm means and thetop wall portion which is fixed thereto toward the teat in the directionof flow of the liquid baby food from the container to the nipple when inuse; and

d. a nipple cap covering at least the teat of said nipple andmaintaining the covered portion of the nipple and the secondary sterilezone in sterile condition during storage.

2. A nursing unit in accordance with claim 1 wherein the arm partdisposed at an angle to said surface is positioned in the secondarysterile zone.

3. A nursing unit in accordance with claim 2 whereinsaid one part of thearm means is fixed to a section of said top wall of the container whichis structurally weaker than adjacent sections of the top wall and thusmore easily rupturable than said adjacent sections.

4. A nursing unit in accordance with claim 1 wherein the arm partdisposed at an angle to said surface is positioned in the primarysterile zone.

5. A nursing unit in accordance with claim 1 wherein said one part ofthe arm means is fixed to a section of said top wall of the containerwhich is structurally weaker than adjacent sections of the top wall andthus more easily rupturable than said adjacent sections.

6. A nursing unit in accordance with claim 3 wherein the structurallyweaker section is thinner than said adjacent sections.

7. A nursing unit including:

a. a sealed container enclosing a primary sterile zone containingsterile liquid baby food;

b. a nursing nipple having an upstanding teat and a base, said nipplebeing attached to said container with said base positioned toward anoutside surface of the container and the teat extending away from thecontainer to provide a secondary, sterile zone bounded by inside wallsof said nipple and that portion of the surface of the container overwhich the attached nipple is located and defined by the attachment ofthe nipple thereto;

c. sterile opening means dispose in one of said sterile zones andoperable without violating the sterility of either said zones comprisingan electrical circuit in contact with a section of the portion of thecontainer in said zones, said circuit comprising electrical leadsextending to the outside of the nursing unit for attachment to a sourceof electrical energy, said circuit when connected to said source heatingsaid section to melt an opening therein; and

d. a nipple cap covering at least the teat of said nipple andmaintaining the covered portion of the nipple and the secondary sterilezone in sterile condition during storage.

UNITED STATES PATENT oFFicE CERTIFICATE OF ORRECTION Patent No. 3 635724 Dated January 18 1972 Inventor-(s) Charles H. Schaar It is certifiedthat error appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 1, line 66, for "and" read of the column 1, line 69, for "the"read and column 2, line 43, for "an" read and column 3, line 1, for"the" read this column 3 line 4, after "nipple" insert has a column 3,line 27, strike out "to"; column 3 line 46, for "bacterial" readbacteria column 3, line 50,

for "was" read has column 4, line 31, for "the" read Signed and sealedthis 6th day of March 1973.

(SEAL) Attest:

EDWARD M.PLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents FORM PO-105O (10-69) USCoMM-Dc 5o375.p g

# U.S, GOVERNMENT PRINTING OFFICE: 1969 0-365-334

1. A nursing unit including: a. a sealed container defined by top,bottom and side walls, said container enclosing within said wall aprimary sterile zone containing sterile liquid baby food; b. A nursingnipple having an upstanding teat and a base, said nipple being attachedto said container with said base positioned toward and over the outsidesurface of the top wall of the container and the teat extending awayfrom the container to provide a secondary sterile zone bounded by insidewalls of said nipple and the outside surface of the top wall of thecontainer over which the attached nipple is located; c. sterile openingmeans disposed within one of said sterile zones comprising an arm meanshaving one part thereof fixed to the top wall of said container overwhich the attached nipple is located and an arm part extending beyondthe fixed part disposed at an angle to the surface of said top wall ofthe container to provide a lever arm which is operable without violatingthe sterility of either of said zones by application of a load theretoto cause the top wall of the container to rupture at the place whEre thearm means is fixed thereto to create an opening therethrough and todisplace said fixed part of the arm means and the top wall portion whichis fixed thereto toward the teat in the direction of flow of the liquidbaby food from the container to the nipple when in use; and d. a nipplecap covering at least the teat of said nipple and maintaining thecovered portion of the nipple and the secondary sterile zone in sterilecondition during storage.
 2. A nursing unit in accordance with claim 1wherein the arm part disposed at an angle to said surface is positionedin the secondary sterile zone.
 3. A nursing unit in accordance withclaim 2 wherein said one part of the arm means is fixed to a section ofsaid top wall of the container which is structurally weaker thanadjacent sections of the top wall and thus more easily rupturable thansaid adjacent sections.
 4. A nursing unit in accordance with claim 1wherein the arm part disposed at an angle to said surface is positionedin the primary sterile zone.
 5. A nursing unit in accordance with claim1 wherein said one part of the arm means is fixed to a section of saidtop wall of the container which is structurally weaker than adjacentsections of the top wall and thus more easily rupturable than saidadjacent sections.
 6. A nursing unit in accordance with claim 3 whereinthe structurally weaker section is thinner than said adjacent sections.7. A nursing unit including: a. a sealed container enclosing a primarysterile zone containing sterile liquid baby food; b. a nursing nipplehaving an upstanding teat and a base, said nipple being attached to saidcontainer with said base positioned toward an outside surface of thecontainer and the teat extending away from the container to provide asecondary, sterile zone bounded by inside walls of said nipple and thatportion of the surface of the container over which the attached nippleis located and defined by the attachment of the nipple thereto; c.sterile opening means dispose in one of said sterile zones and operablewithout violating the sterility of either said zones comprising anelectrical circuit in contact with a section of the portion of thecontainer in said zones, said circuit comprising electrical leadsextending to the outside of the nursing unit for attachment to a sourceof electrical energy, said circuit when connected to said source heatingsaid section to melt an opening therein; and d. a nipple cap covering atleast the teat of said nipple and maintaining the covered portion of thenipple and the secondary sterile zone in sterile condition duringstorage.